Prefabricated denture construction and method

ABSTRACT

Denture bases in a plurality of standard sizes are mass produced and stocked by dentists in order to fit and tailor a set of artificial dentures to an individual patient during a single visit. The standard denture bases are made by use of reusable mold assemblies which include cavity-forming bodies made of an elastically deformable material.

United States Patent Weinkle [54] PREFABRICATED DENTURE CONSTRUCTION ANDMETHOD [72] inventor: Milton L. Weinkle, 420 Lincoln Road,

Miami, Fla. 33139 [22] Filed: Sept. 29, 1969 [21] Appl. No; 861,617

[52] [1.8. CI [51] Int. Cl [58] Field of Search ..32/2, 8; l8/5.7

[56] References Cited UNITED STATES PATENTS 2,165,597 7/1939 Widoe, Sr...32/2 2,466,727 4/1949 Morgan ..32/ 2 2,596,941 5/ 1952 Quintella..32/2

[ 1 Feb. 29, 1972 2,659,970 11/1953 lngersoll, Jr. ..32/2 2,685,1338/1954 Greene et al. ..32/2 2,790,237 4/ 1957 Chaiken .3212 2,899,7128/1959 Smith ...32/2 3,251,909 5/1966 Pickands et al.. ...32/2 3,335,4958/ 1967 Wichner ...32/2 3,464,! 11 9/1969 Gillard ..32/2

Primary Examiner-Robert Peshock Attarney-Clarence A. OBrien and HarveyB..Jacobson [57] ABSTRACT Denture bases in a plurality of standard sizesare mass produced and stocked by dentists in order to tit and tailor aset of artificial dentures to an individual patient during a singlevisit. The standard denture bases are made by use of reusable moldassemblies which include cavity-forming bodies made of an elasticallydeformable material.

5 1 Claim, 6 Drawing Figures PREFABRICATED. DENTURE CONSTRUCTION ANDMETHOD This invention relates to the manufacture and fitting ofartificial dentures.

The method of making and fitting artificial dentures in general usetoday, is relatively. time-consuming as well as expensive. Thus, forpersons of low income in need of artificial dentures, an excessiveeconomic burden is involved while for others, present methods areobjectionable because of the inconvenience of time delays anddiscomforts incident thereto. Present methods ofmaking and fittingartificial dentures usually involve many visits to the dentists oflicein order to obtain impressions from which models are made, waitingperiods between removal of teeth and fitting of dentures, custommanufacture of the dentures in a dental laboratory after. aselection ofartificial teeth size and color is made as well as. tryouts, adjustmentsand finishing of the dentures. Fabrication of the dentures themselves ina dental lab usually involves waxingof models mounted on an articulatorwhich simulates movement of the patients jaws, positioning of artificialteeth in order to approximate occlusal relationships, and casting thedentures in plaster molds made from the waxed up models.

The use of standard size dentures capable of being lined with -amoldablematerial so that it may be tailored to an individuals mouth, has beenproposed, for example, in US. Pat. Nos. 2,685,133 and 3,335,495. Whilethe methods disclosed in these patents represent an attempt to reducethe time involved in making and fitting artificial dentures byeliminating custom fabricating methods in present use, the techniquesdisclosed in these patents have not been adopted for several reasons.

While US. Pat. No. 2,685,133 to Greeneet al. discloses the concept offabricatingstandard'size dentures, the value of making standard sizedentures is lost unless they can be mass produced. Present known methodsfor making dentures are unsuitable since the plaster molds made indental laboratories are not reusable and are destroyed or ruptured uponremoval of the. denture from the mold.

U.S. Pat. No. 3,335,495 to Wichner is limited to the assembly ofartificial teeth with the denture base utilizingan intermediate blankfor this purpose. While it is desirable to interchangeably assembleartificial teeth with denture bases'in order to increase the number ofdenture combinations from which a selection may be made in order to fitan individual patient, from the standpoint of cost andstructuraldurability the use of an additional intermediateblank isunsatisfactory.

it is therefore an important object of the present invention to providea method for making and fitting artificial dentures utilizing standardsize denture bases but avoiding the drawbacks associated with thedisclosures in US. Pat. Nos. 2,685,133 and 3,335,495 aforementioned.Further, in accordance with the foregoing object, the present inventionrepresents the first practical basis upon which artificial dentures maybe fitted to individual patients by selection from standard size denturebases, utilizing the services of qualified practitioners in the dentalprofession.

in accordance with the present invention, standard size denture basesare capable of being mass produced by casting thereof in reusable molds.Toward this end, a sectional mold assembly is utilized made of anelastically deformable material within which the mold cavities areformed. Thus, removal of the cured denture base fromthe mold merelycauses temporary deformation thereof without permanent distortion orrupture. A plurality of acrylic denture bases in different standardsizes may therefore be produced economically and stocked by each dentistemploying the techniques of the present invention. A denture base maythen be selected and fitted to an individual patient as described. forexample in U.S. Pat. No. 2,685,133 to Greene et al. aforementioned.Also, a separate selection may be made of the artificial teeth both tothe size and color by the dentist to suit the patient being fitted. Inrare cases, the selected denture base may be cut or relieved in order toaccommodate the patients mouth. The denture base may then be tailored tothe patients mouth by lining thereof with the same acrylic denture basematerial in its plastic state. Thus, after the molded lining materialhas set, the excess is removed and the denture finished. The foregoingprocedure may be carried out during a single visit to the dentist. Asidefrom the economy incident to the mass production of standard sizedenture bases as compared to custom fabrication in accordance withpresent methods, the present invention involves a considerable savingsin time and less discomfort for the patient by making the denture basemoldable lining; technique feasible.

These-together with other objects and'advantages which'will becomesubsequently apparent reside in the details of construction andoperation as more. fully hereinafter described and claimed, referencebeing had to the accompanying drawings forrninga part hereof, whereinlike numerals refer to like parts throughout, and in which:

FIG. 1 is a block diagram diagrammatically'illustrating the method ofthe present invention.

HO. 2 is a perspective view of the parts utilized in fitting andassembling apreformed denture in accordance with the present invention.

FIG. 3 is a partial sectional view taken substantially through a planeindicated by section line 3-3 in H6. 2.

FIG. 4 is an enlarged partial sectional view taken substantially througha plane indicated by section line 4-4 in H0. 2.

FIG. 5 is a sectional view through a sectional mold constructed inaccordance with the present invention for casting a preformed, standardsize denture.

FIG. 6 is a sectional view through a completed denture constructed andfitted in accordance with the present invention.

Referring now to the drawings in detail, FIGS. 2 and 3 illustratetypical parts which will be stocked in standard sizes by a dentist inorder to practice the present invention. These parts include disposableridge forms adapted to be inserted into a patients mouth in order tooccupy the space normally occupied by an artificial denture, such as theupper "ridge form 10. it will of course be appreciated that there willalso be standard size ridge forms adaptedto fit the lower jaw. The ridgeforms are made of a relatively inexpensive, thin, transparent plasticmaterial 12. These ridge fomis are stocked in standard sizes, therebeingup to 10 sizes in order to accommodate something like percent of allpersons. Thus, with a set of corresponding standard size denture basescorresponding to the ridge forms, the standard size denture basedimensionallycloscst to a patient may be determined, such as the denturebase 14 shown in FIGS. 2 and 3. Thedenture base is made of the sameacrylic plastic as artificial denture bases heretofore custom made inaccordance with present methods but differs therefrom in that the innersurface 16 of the denture base will not exactly conform to the tissuesurfaces of the patient being fitted. Further, in one embodiment of theinvention, the standard size denture base 14 is provided with aplurality of sockets 18 adapted to receive artificial teeth to beassembled with the denture base.

At the present time, it is contemplated that therewillbe 10 standardsize upper and lower ridge forms and corresponding standard size upperand lower'denture bases. Also, artificial teeth of standard size andcolor will be stocked by the'dentist so that a selection may be made inaccordancewith the size and color of teeth removed from a patient. Theentire procedure in making and fitting dentures from the standard sizedparts aforementioned is diagrammed in FIG. 1. As shown, the presentinvention contemplates mass production of the standard size ridge forms10 and denture bases 14 from reusable molds 20 employing an injectionmolding process 22. FIG. 1 also diagrams the stock of artificial teeth24 which may either be cast with the denture bases or embedded in themolds in order to directly bond the same to' the denture bases as analternative to subsequent bonding of the artificial teeth within thesockets 18 of the denture bases as shown in F168. 2 and 3. P10. 1 alsodenotes the fitting step 26 by means of which the standard size denturebase dimensionally closest to the jaw of the patient is determined sothat a proper selection and assembly may be made as denoted by referencenumeral 28. If necessary, the denture base may be cut in order toaccommodate certain patients as denoted by reference numeral 30. Theassembled denture is then lined on the inner surface by moldable liningmaterial as denoted by reference numeral 32 in H6. 1 in order to tailorthe denture to the jaw of the patient. After curing of the acryliclining, any excess is removed and rough spots polished as indicated bythe finishing station 34 in FIG. 1.

As hereinbefore indicated, a selection of artificial teeth is made bythe dentist. The artificial teeth may be cast together with the denturebases or embedded in the molds from which the denture bases are cast fordirect bonding to the denture bases. In the latter case, there will bestandard combinations of denture base sizes and artificial teeth colorsfrom which the dentist must make a selection both as to size and teethcolor. The embodiment illustrated in FIGS. 2, 3 and 4 however involvesassembly of separately cast denture bases 14 and artificial teeth madefrom acrylic or porcelain material. The artificial teeth may be selectedfrom and assembled as separate groups of integrally connnected teethincluding groups of posterior teeth 36 and anterior teeth 38. Each toothwill fit within one of the sockets 18 while bonding facilities will beprovided for the end teeth in each group. The posterior teeth 36 forexample, will include an end molar 40 and an end bicuspid 42 havingrecesses 44 formed therein for receiving projections 46 in those sockets18 of the denture base corresponding to the end teeth. A suitableadhesive may also be utilized to coat the engaging surfaces of thesockets l8 and the end teeth received therein. Similarly, bondingfacilities will be provided for the end teeth associated with theanterior groups 38 such as the cuspids on either side of the incisors.

FIG. illustrates a typical reusable mold assembly 48 within which astandard size lower denture base was cast such as the lower denture 50shown in FIG. 6. ln this example, the artificial teeth 52 were directlybonded to the denture base 54 by embedding the teeth in the reusablemold assembly prior to introduction of the acrylic plastic mixture intothe mold cavity 60. A conventional dental flask was utilized inconnection with the mold assembly including lower and upper flasksections 56 and 66 as shown in FIG. 5. Bodies of elastically deformablematerial 58 and 64 cured from a settable mixture known as RTV" made byDow-Corning Company was utilized exclusively as the cavity formingmaterial. Standard size plaster models on which master dentures werepositioned, were embedded in the mold material 64 and 58 while in aplastic state so as to form the mold cavity 60 between surfaces thereofin the flask sections 56 and 66. Thus, the plaster model itself is notutilized as part of the mold assembly. A separating medium 68 wasutilized between the mold cavity bodies 58 and 64.

With the artificial teeth 52 embedded in the cured mold cavity body 58as shown in FIG. 5, a plastic mixture of the acrylic material wasintroduced into the mold cavity 60 and cured to a rigid state directlybonding to the artificial teeth. The denture so formed was removed fromthe mold cavity without rupturing the mold body material despite theundercutting in the mold cavity in view of the elastically deformableproperty of the mold material. Thus, the mold assembly 48 was reused inorder to form a large quantity of the same standard size dentures.

When a denture selection is made, it is tailored to the individualpatient by lining a plastic mixture of acrylic on the inner surface suchas indicated by reference numeral 70 in FIG. 6. The lining denture maythen be molded directly within the patients mouth making sure thatproper occlusal relationships and requirements are satisfied. After thelining has initially set, the denture may be removed from the patientsmouth and the lining permitted to fully cure. Excess material squeezedout over the ridges of the denture may then be removed by an abrasivetool and rough spots polished in order to complete the denture.

The determination of the denture base size, the selection of artificialteeth, the assembly of the denture, the tailoring of the denture to theindividual patient and the finishing thereof may all be performed duringa single visit to the dentist. The foregoing procedure is of course madefeasible by mass production of the standard size denture bases utilizingreusable molds as hereinbefore described.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention.

lclaim:

1. In a method of making standard size dentures, the steps of: forming amold cavity between surfaces of a least two elastically deformable moldbodies; placing a settable material into the mold cavity to form adenture base; curing the settable material to a relatively rigid state;reusing the cured material from the mold cavity without rupture of themold bodies; reusing the mold bodies to form additional denture baseswithin the mold cavity; casting separate groups of posterior andanterior teeth; and bonding said groups of teeth to the denture bases.

1. In a method of making standard size dentures, the steps of: forming amold cavity between surfaces of a least two elastically deformable moldbodies; placing a settable material into the mold cavity to form adenture base; curing the settable material to a relatively rigid state;reusing the cured material from the mold cavity without rupture of themold bodies; reusing the mold bodies to form additional denture baseswithin the mold cavity; casting separate groups of posterior andanterior teeth; and bonding said groups of teeth to the denture bases.